[U-Boot] [PATCH 01/11] imx: Add bootcmd to load and run UEFI from mmc

[Henry Beberman]

> -----Original Message-----
> From: Alexander Graf <agraf at suse.de>
> Sent: Tuesday, August 7, 2018 6:46 AM
> To: Tom Rini <trini at konsulko.com>
> Cc: Stefano Babic <sbabic at denx.de>; Henry Beberman
> <Henry.Beberman at microsoft.com>; u-boot at lists.denx.de; Fabio Estevam
> <fabio.estevam at nxp.com>
> Subject: Re: [PATCH 01/11] imx: Add bootcmd to load and run UEFI from
> mmc
> 
> 
> 
> > Am 07.08.2018 um 12:16 schrieb Tom Rini <trini at konsulko.com>:
> >
> >> On Tue, Aug 07, 2018 at 01:11:11PM +0200, Stefano Babic wrote:
> >> Hi Henry,
> >>
> >>> On 14/07/2018 02:11, Henry Beberman wrote:
> >>> From: Henry Beberman <henry.beberman at microsoft.com>
> >>>
> >>> This patch enables i.MX platforms to easily add a boot script to
> >>> their U-Boot Proper environment to automatically load and execute an
> >>> EFI firmware from the first FAT partition of an MMC device.
> >>>
> >>> This is a portion of enabling the Windows 10 IoT Core boot path.
> >>>
> >>> The go command is overridden when CONFIG_UEFI_BOOT is specified.
> >>> This new go will perform a cache flush/disable, disable interrupts,
> >>> then jump to the address where UEFI was loaded.
> >>>
> >>> This patch adds two new Kconfig options:
> >>> CONFIG_UEFI_BOOT: Selects the UEFI bootcmd and overrides go to
> flush
> >>> caches and disable interrupts.
> >>> CONFIG_UEFI_LOAD_ADDR: Specifies the load address for the UEFI
> image
> >>>
> >>> Signed-off-by: Henry Beberman <henry.beberman at microsoft.com>
> >>> Cc: Stefano Babic <sbabic at denx.de>
> >>> Cc: Fabio Estevam <fabio.estevam at nxp.com>
> >>> Cc: Tom Rini <trini at konsulko.com>
> >>> ---
> >>> arch/arm/mach-imx/Makefile    |  1 +
> >>> arch/arm/mach-imx/boot.c      | 19 +++++++++++++++++++
> >>> common/Kconfig                | 17 +++++++++++++++++
> >>> include/config_uefi_bootcmd.h | 29
> +++++++++++++++++++++++++++++
> >>> 4 files changed, 66 insertions(+)
> >>> create mode 100644 arch/arm/mach-imx/boot.c create mode 100644
> >>> include/config_uefi_bootcmd.h
> >>>
> >>
> >> I am really missing why we need this specially for i.MX. There is
> >> nothing special to i.MX, and if this command is necessary, we should
> >> put it in common code.
> >>
> >> Anyway, should we not try to merge it with the general support for
> >> UEFI in U-Boot ? We have already a "bootefi" command (aarch64 and
> >> x86, currently).
> >
> > Agreed, this should be folded in with our existing UEFI support, thanks!
> 
> Yes, please just use distro boot. Bootefi (which distro boot calls) already
> supports running UEFI binaries for real even on armv7.
> 
> 
> Alex
> 

Running Windows directly on U-Boot through bootefi is definitely appealing, but
we're dependent on a number of features provided by our full UEFI firmware.

* Several ACPI tables that are unimplemented in U-Boot: CSRT, DBG2, SPCR, TPM2, GTDT
* Some DSDT elements that require the Microsoft ASL compiler (for now)
* UEFI Authenticated Variables that are writeable at runtime.
* UEFI Secure Boot
* Launching and communicating with a Firmware TPM running as an OP-TEE Trusted Application

I'd be happy to break down this patch's changes into more generic steps rather than
creating confusion by adding CONFIG_UEFI_BOOT.

I can move the UEFI binary into our FIT to eliminate the custom binary load script. 
How should I cleanly add an alternate CONFIG_BOOTCOMMAND to an existing board.h file?
Where is the best place to define an alternate do_go_exec that calls
cleanup_before_linux() before jumping?

Thanks,
Henry